1. Field of the Invention
The present invention relates to housings for small base stations used in cellular communication (frequently known as "microcells").
2. Description of Related Art
Cellular wireless communication is based on the use of base stations in respective geographical cells to transmit and receive calls. "Macrocells" range in size from tens of miles in rural areas to a mile or less in more metropolitan regions. However, traffic density can foreseeably become so high that a cell with even a one mile radius can become overloaded. Accordingly, much smaller cells ("microcells") are used and have coverage regions of tens of yards to hundreds of yards in radius. (See, for example, Kuruppillai et al., Wireless PCS, McGraw-Hill, 1997, p. 377.)
Physically, a microcell base station is relatively small (especially compared to the antenna towers of macrocells). A housing for a microcell base station may, for example, be 10 inches deep, 24 inches wide, and 24 inches high. The microcell base station comprises a housing for electronics and circuitry conventionally known in the field of cellular communication.
To the extent that microcell base stations are frequently located outdoors, it is important to maintain a particular operating temperature range within the base station housing, at least so the electronic elements therein are not unduly affected by variations in ambient temperature. For example, electric resistance in electronic components is very temperature dependent.
Conventionally, housings for microcell base stations have addressed issues of cooling, utilizing, for example, convection cooling, heat sink behavior based on metal materials used for the housing, and heat transfer fins to facilitate heat dispersion.
The issue of heating such housings has been known relative to air-cooled housings where heaters and fans to move heated air are provided. However, in convection-cooled housings, heating has not been heretofore provided.